Many formulations are available for application to the skin for various effects including cosmetic effects and medicinal treatment, or even both purposes concurrently. Such formulations exist in the form of liquids, gels, lotions, creams, ointments, mists, sprays, etc.
One reason for treating skin is to alter its color or tone, such as by lightening (whitening), or darkening (or tanning). Various conditions of the skin, including genetic, injury and disease, irritation, sometimes cause areas of undesirable discoloration such as age spots, burns, blotches, rashes, scar tissue, birth marks, and other things often give rise to the desire to alter skin color. Additionally, purely aesthetic concerns sometimes underlay the desire to alter skin color to achieve more even tone, lighter tone or darker tone.
Just as there are tanning lotions and sprays which darken skin tone, there are also skin lightening formulations which are used to lighten or whiten skin tone. While some such skin care formulations take time to produce the desired skin lightening effect, consumers would appreciate also having skin care formulations available which produce lightening or whitening effects quickly, and even immediately.
For example, US Patent Application Publication No. 2006/0018861 discloses a skin care composition for lightening skin tone which comprises a flavanoid component, a vitamin B3 compound, and an oil-in-water carrier, as well as various other optional ingredients. The combination of the flavanoid and vitamin B3 is described as providing a synergistic skin lightening effect. US Patent Application Publication No. 2006/0018861 also describes the use of more conventional skin tone changing and lightening agents, such as pigments, reflective particulate material and mixtures thereof. More specifically, examples of suitable pigments include talc, mica, silica, magnesium silicate, titanium oxide and zinc oxide. Examples of suitable reflective particulate materials include inorganic compounds such as titanium dioxide and zinc oxide. Other typical skin lightening agents mentioned in US Patent Application Publication No. 2006/0018861 include active ingredients that improve hyperpigmentation, including ascorbic acid compounds, azelaic acid, butyl hydroxyanisole, gallic acid and its derivatives, glycyrrhizinic acid, hydroquinone, kojic acid, arbutin, mulberry extract, and mixtures thereof. It is also pointed out that use of combinations of skin lightening agents is believed to be advantageous in that they may provide skin lightening benefit through different mechanisms. US Patent Application Publication No. 2006/0018861 further suggests that poly(ethylene) oxides and carboxylic acid/carboxylate copolymers are both among various compounds useful as viscosifying agents in the skin care composition described therein, though there is no indication that such compounds contribute in any way to the desired skin lightening effect.
The skin care industry would welcome alternative formulations that produce skin lightening or whitening effects that do not require particulate ingredients, such as pigments and reflective materials, or acidic ingredients such as those mentioned above. The present invention provides a skin care formulation which provides a skin lightening effect virtually immediately upon topical application to the skin and which includes a combination of one or more poly(ethylene) oxides and an acrylic emulsion polymer film former comprising emulsion polymers derived from one or more ethylenically unsaturated monomers.